Biodiesel is produced by transesterification of animal fat, vegetable oil, or waste cooking oil with an alcohol, producing the desired biodiesel fuel along with glycerol as a byproduct. A number of studies have focused on the evaluation of the economic viability of biodiesel.2-5 Production costs are approximately 0.5 USD/L, 1.5 times that of petroleum-based diesel, with virgin feedstocks comprising 50 to 70% of costs.3,4 The feedstock costs can be reduced through the use of waste cooking oils and similar products, but these materials increase the complexity of synthesis and, often, the presence of contaminants.5 In addition to providing a renewable source of energy, biodiesel is attractive as an alternative fuel due to related reduced environmental impact; use of these fuels decreases emission of atmospheric pollutants.6 Procuring water together with liquid and solid waste disposal comprise up to 10% of manufacturing costs,3,4 while also influencing the environmental impact of this alternative fuel source. As an example, multiple wash steps for biodiesel purification can generate gallons of waste water for each gallon of usable biofuel. Biodiesel contaminants include glycerol, alcohols, free fatty acids, surfactants, and residual catalyst. Glycerol, while a contaminant in biodiesel, can be recovered and purified to aid in offsetting the costs of biodiesel production.4 
Contaminants (including glycerol) can be removed from biodiesel via the use of dry wash media as an alternative or partial replacement for water washing. Currently, use of dry wash media for cleaning biodiesel is largely limited to small operations and hobbyists. Using dry wash media avoids excessive waste water production while reducing production time and requiring less space when compared to water washing. BD ZorbX and DudaLite (DW-R10®) ion exchange resin are commercial examples of types of materials used for this purpose. BD ZorbX is a mixture of cellulose fibers from hardwood intended to absorb a variety of contaminants including surfactants, glycerol, and catalyst; Eco2Pure™ is a similar material. DW-R10 is intended as a polishing step following bulk glycerol removal, and it is claimed to remove surfactants, glycerol, catalyst, and water. Drionex, Purolite® PD206, and Magnesol D-Sol are intended for similar applications.
A need exists for alternative sorbent materials.